1. Field of the Invention
This invention relates to blood analyzers, and more particular to portable blood analyzers capable of analyzing multiple analytes.
2. Description of Related Art
Blood analyzers are medical instruments capable of analyzing one or more analytes, such as blood values for oxygen, carbon dioxide, pH, hematocrit, and electrolytes, such as potassium, sodium, and calcium ions. Most prior art blood analyzers capable of measuring more than one analyte are complex, requiring specialized service skills and operator experience. Such multiple analyte blood analyzers have generally weighed in excess of 30 pounds, and have had sensor electrodes and plumbing (fluid path) that are complicated and require specialized knowledge to service. Many such blood analyzers require tonometered gases in rigid or semi-rigid tanks to calibrate the sensors.
Prior blood analyzers have also often suffered from problems relating to clotting or blockage by proteinaceous materials which occlude fluid handling elements of the instrument. Analyzers which carry blood samples over long distances through multiple banks of electrodes are more susceptible to such problems. Also, blood elements tend to obstruct traditional valving systems. When blood obstruction occurs in instrumentation, intensive disassembly and servicing has generally been required. Generally, blood analyzers having longer blood paths have more valves, and are generally complex and costly.
Accordingly, after noting the limitations of the above-described prior art, the inventors of the present invention have devised a new blood analyzer that overcomes these problems.